51642740 has 24 divisors (see below), whose sum is σ = 108599400. Its totient is φ = 20628608.

The previous prime is 51642697. The next prime is 51642761. The reversal of 51642740 is 4724615.

It can be written as a sum of positive squares in 4 ways, for example, as 2137444 + 49505296 = 1462^2 + 7036^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18986 + ... + 21534.

It is an arithmetic number, because the mean of its divisors is an integer number (4524975).

Almost surely, 2^51642740 is an apocalyptic number.

It is an amenable number.

51642740 is an abundant number, since it is smaller than the sum of its proper divisors (56956660).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51642740 is a wasteful number, since it uses less digits than its factorization.

51642740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3571 (or 3569 counting only the distinct ones).

The product of its (nonzero) digits is 6720, while the sum is 29.

The square root of 51642740 is about 7186.2883326513. The cubic root of 51642740 is about 372.3943576825.

The spelling of 51642740 in words is "fifty-one million, six hundred forty-two thousand, seven hundred forty".